Why record visual acuity in children ? :

Why record visual acuity in children ? Most eye problems can be treated if detected early
Useful in decision making
To know if visual development is normal
Helps decide eligibility for low vision and rehabilitation services

History :

History In mid 1950s, with the establishment of the Allen cards, development of pediatric acuity testing techniques were reported

Fixation Maintain :

Fixation Preference :

Fixation Preference Place a 10D base down prism in front of one eye
Alternate fixation indicate equal visual acuity in both eyes
If fixation does not maintain then preferred eye occluded
If fixation is maintained through a blink, then also visual acuity is good

Optokinetic Nystagmus :

Optokinetic Nystagmus OKN drum consist of
white and black strips rotates in front of infant’s eye
Examiner has to follow the fixation movement
of patient’s eye

Force Choice Preferential Looking Test :

Force Choice Preferential Looking Test Infants prefer to fixate high contrast bold strips rather than homogenous field of light
Two target and a central fixation light at infant’s eye level
Examiner has to become familiar with the child’s looking style
First fixation
Duration of fixation
Facial expression of patient

Visual Evoked Potential / Visual Evoked Cortical Potential :

Visual Evoked Potential / Visual Evoked Cortical Potential A checkerboard stimulus
phase altered at a rate of
6 cycle/sec in front of the
patient’s eyes
A electrode placed on skull over occipital lobe
Result is compared with the VEP of adult

Methods of testing Visual Acuity in Toddlers :

Hundred and Thousand Sweet Test :

Hundred and Thousand Sweet Test A very sweet test
If child able to pick up small sweets at 33 cm, visual acuity is at least 6/24 or 20/80

The Cardiff Acuity Test :

The Cardiff Acuity Test The principle of the target design is that of the vanishing optotype
The targets are pictures drawn with a white band bordered by two black bands, all on a neutral grey background
The examiner simply observes the child’s fixation

Dott Visual Acuity Testing :

Administration of Tests in Preschoolers :

Administration of Tests in Preschoolers Step 1
A pretest to teach and check the child's reliability in responding to the test
Step 2
A test to assure that the child’s responses are reliable at 10ft (3m)
Step 3
Actual measurement of acuity level at 10ft (3mt)

Methods of testing Visual Acuity inPreschoolers :

LEA Symbols test :

LEA Symbols test Task is to match and point out the distance target
10 feet distance
pictures--circle
square
house
apple

Light House Flash Card Testing :

Light House Flash Card Testing 12 cards are available, size of each card is
4×5 inch
These cards have three types of picture target
Target size available from 20/200 – 20/10
In 20/200 card we have 20/100 target size on the reverse side

Allen Picture Card :

Broken Wheel Test :

Broken Wheel Test Here cards are presented with
picture of a car, very familiar
to the child
Two cards are held before the
child, he simply has to recognize
which one is broken
It consist of 8 pairs of test cards and a sample pair of card
(equivalent to 20/120 test size)

Tumbling E chart :

Tumbling E chart English E letter is used in different directions
The child has to detect the orientation of the limbs
Simons introduced use three directions to avoid confusion

Landolt C chart :

Landolt C chart Sjogren hand test

HOTV Test :

HOTV Test Optotypes are used to avoid left right confusion
Child has to identify the letter optotypes